UFRGS-HEP Journal Club

America/Sao_Paulo
IF-UFRGS

IF-UFRGS

Gustavo Gil Da Silveira (Universidade do Estado do Rio de Janeiro (BR))
    • 13:30 14:30
      Tulio Kuhn 1h

      Measurement of the Higgs boson width and evidence of its off-shell contributions to ZZ production
      [CMS Collaboration]
      Nat. Phys. 18 (2022) 1329
      Hide abstract | Show figures | Show BibTeX | Show discussion | View PDF | 2202.06923v2

      Since the discovery of the Higgs boson in 2012, detailed studies of its properties have been ongoing. Besides its mass, its width - related to its lifetime - is an important parameter. One way to determine this quantity is by measuring its off-shell production, where the Higgs boson mass is far away from its nominal value, and relating it to its on-shell production, where the mass is close to the nominal value. Here, we report evidence for such off-shell contributions to the production cross section of two Z bosons with data from the CMS experiment at the CERN Large Hadron Collider. We constrain the total rate of the off-shell Higgs boson contribution beyond the Z boson pair production threshold, relative to its standard model expectation, to the interval [0.0061, 2.0] at 95% confidence level. The scenario with no off-shell contribution is excluded at a p-value of 0.0003 (3.6 standard deviations). We measure the width of the Higgs boson as ΓH = 3.2 +2.4−1.7 MeV, in agreement with the standard model expectation of 4.1 MeV. In addition, we set constraints on anomalous Higgs boson couplings to W and Z boson pairs.
      Authors' comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-21-013 (CMS Public Pages). Nat. Phys. (2022)